1. FIELD OF THE INVENTION
This invention relates to new and useful improvements in adjustable pitch drums and more particularly to a separate independently adjustable pitch drum head having supporting means securing the same on and spaced from a drum shell.
2. BRIEF DESCRIPTION OF THE PRIOR ART
A conventional drum consists of a cylindrical drum shell having drum heads held in place by head hoops. Conventional drums are usually not tuneable except in a very narrow range by adjustment of the head hoop.
A RotoTom is a recently designed adjustable pitch drum manufactured by Remo, Inc. of North Hollywood, Calif. The RotoTom is in public use and on sale but is not described, per se, in any patent or published literature other than a limited amount of advertising literature available from the manufacturer. The RotoTom has a stand and a threaded shaft which extends upward and terminates in an end portion which abuts the head of the drum. The drum consists of a single head mounted on a supporting hoop and supported on a rigid multi-legged spider support. The spider is secured on a threaded tubular support which rides on the threaded shaft. Rotation of the supporting hoop by the drummer causes the threaded support to move upward and downward on the threaded shaft and vary the tensioning force against the drum head to tune the same.
May U.S. Pat. Nos. 4,048,895; 4,121,493 and 4,122,748 disclose adjustable pitch drums in which a RotoTom is supported on an open end of a drum shell by a supporting spider. The threaded rod which supports the RotoTom is threadedly supported in the last-named supporting spider and is adjustable to vary the position of the RotoTom drum head from the drum shell as well as permitting the independent tuning of the drum head.
The adjustable pitch drum shown and described in the aforementioned May Patents has been introduced commercially and has been well received under the name "Vari-Pitch" Drum. This adjustable pitch drum, however, has a slight disadvantage in that the adjustable supporting structure which fits within the drum shell interferes with the reflected sound waves in the drum shell and does not yield the purity of sound desired by a musician with a very sensitive ear for fine distinctions in tone and pitch. The interference of sound waves by the internal supporting structure is noted particularly when the drum is electrically amplified as disclosed in May U.S. patent application Ser. No. 927,543, filed July 24, 1978.
Accordingly, there is a need for an adjustable pitch drum in which substantially all of the adjusting structure is located external to the drum shell.